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  1. #include <stdio.h>
  2. #include <stdlib.h>
  3.  
  4. typedef struct series series;
  5. struct series {
  6. 	long num;
  7. 	series *next;
  8. };
  9. series *head = NULL;
  10.  
  11. void addhead(long x)
  12. {
  13. 	series *p;
  14. 	p = (series *) malloc(sizeof (series));	
  15. 	p->num = x;
  16. 	p->next = head;
  17. 	head = p;
  18. 	//printf("added: %ld\n", x);
  19. }
  20. void series_generate(long num)
  21. {
  22. 	long n = 1;
  23. 	addhead(n);
  24. 	while (n < num) 
  25. 	{
  26. 		series *p;
  27. 		for (p = head; p != NULL; p = p->next)
  28. 		{
  29. 			long bf = p->num - 1;
  30. 			if (p->num%2 == 0 && bf != 0 && bf%3 == 0) {
  31. 				bf /= 3;
  32. 				if (bf != 1)
  33. 				addhead(bf);
  34. 				if (bf < num)
  35. 					n++; 
  36. 				//printf("new num: %ld\n", bf);
  37. 			}
  38. 			p->num *= 2;
  39. 			if ( p->num < num)
  40. 				n++;
  41.  			//printf("new num: %ld\n", p->num);
  42.  
  43. 		}	
  44. 	}	
  45. }
  46. int main()
  47. {
  48. 	long num = 1000000;
  49. 	series_generate(num);
  50. 	series *p;
  51. 	for (p = head; p != NULL; p = p->next) {
  52. 		if (p->num < num) {
  53. 			printf("%ld\n", p->num);
  54. 			break;
  55. 		}
  56. 	}
  57. 	return 0;
  58. }
Success #stdin #stdout 0.09s 11840KB
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-178956971
https://ideone.com/4QIZX
language:
C (gcc 8.3)
created:
11 years ago
visibility:
public

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